How do I Select the Correct Running Shoe?
Jeffrey Rocco, M.D.
Orthopedic Foot and Ankle Surgeon
One of the most important pieces of equipment for endurance athletes is their running shoes. While the correct shoes can’t do your workout for you, they can support you and protect you from injury in your quest for a PR. The wrong running shoe can be an impediment to your training, and in some cases may even be the source of injury. Ongoing biomechanical stresses perpetuated by the wrong running shoe may also prevent an injury from ever healing.
In addition to proper sizing, the correct running shoe should match an athlete’s foot morphology (shape). With regards to sizing, the shoe should fit snugly in the heel and should have plenty of room to wiggle the toes. Feet tend to swell when running, and if your toes are touching the end of the shoe, you will probably end up losing toenails. To check the length of the shoe simply stand up and place your thumbnail at the end of the longest toe. There should be about half of a thumbnails length between the tip of the toe and the end of the shoe. In general most people end up with a running shoe that is sized one size larger than their street shoe.
Foot morphology covers a spectrum from Cavus (high-arched), to Neutral, to Planus (flat or low-arched). Running shoe manufacturers produce shoes to fit these three categories of feet. How do you know what type of foot you have? One way of checking foot type is the wet footprint test where the foot is dipped into a pan of water and then placed onto paper where the foot shape is examined. I find this test messy, and the results can vary according to how much water is on the foot, how absorbent the paper is, or how much pressure is applied to the paper. I propose a simpler test that requires the help of a friend or a mirror. Simply stand with both feet pointing straight ahead with a comfortable 6”-12” between the feet. Using a mirror or your friend, look at your feet. If your heels can be seen to the medial (inside) side when viewed from the front, you have a cavus foot. If your heels line up directly under your legs, and cannot be seen from the front, you have neutral feet. If the heels line up to the lateral (outside) side you have planus feet.
Now that you know what foot type you have, what shoe should you be wearing? The three major categories of running shoes are Neutral cushioning, Stability, and Motion Control. A neutral shoe offers cushioning without extra support for the arch. Neutral shoes are best for cavus feet and for neutral feet with borderline high arches. Stability shoes offer extra construction on the medial side of the shoe to help support the arch. Stability shoes are best for mild to moderately planus feet. Motion control shoes offer the greatest amount of medial support and are best suited to very flat feet.
Cavus to Neutral Feet = Neutral Shoes
Upper left-note “peek-a-boo heels” typical of cavus feet. Upper right-note heels tip varus (medial). Bottom-note heel varus corrects to neutral when standing on Coleman Block—this indicates hindfoot is supple and can be helped with Cavus orthotic and Neutral running shoe.
As the pictures above illustrate, the cavus foot tips to the lateral (outside) due to the plantarflexed first metatarsal (Big toe curves down toward the floor). This is the opposite of pronation, sometimes called supination. The cavus foot also tends to be stiff and not absorb shock very well. Injuries associated with the cavus foot include recurrent ankle sprains, stress fractures of sesamoids, metatarsals, tibia or fibula, peroneal tendon injuries, iliotibial band syndrome, lateral hip trochanteric bursitis—just to name a few. This foot demands a neutral cushioning shoe. A shoe with stability or motion control features (stiffer material under the arch compared to the lateral side of the shoe) can cause or exacerbate any of the injuries mentioned above.
Mild to Moderately Flat Feet =Stability Shoes
Left—heels are not visible from the front. Right–heels are aligned slightly valgus or lateral. These feet will do best with moderate support provided by stability shoes.
Some people may call these feet mild pronators. They have mildly low arches and mechanics can be helped by modest arch support. They are flexible, absorb shock well, and tend to be less symptomatic than the rigid, high-arched foot.
Flat to Very Flat Feet = Motion Control Shoes
Left—The forefoot appears to roll lateral as the arch drops. The center of the foot—between the second and third toes lines up well lateral of the middle of the leg. Right—There is little to no medial arch and the heel tips lateral. These feet need motion control shoes.
The lowest arches generally need the most support. These feet may be symptomatic along the posterior tibial tendon anywhere from the middle of the arch to the medial side of the ankle or leg. The posterior tibial tendon can be sore from working overtime to support the foot. In severe cases, the lateral side of the ankle may also be sore from impingement as the heel tips lateral and compresses the peroneal tendons against the fibula (lateral ankle bone). Mechanical support from motion control shoes with or without custom arch supports can help to prevent these symptoms.
These three major foot types and shoe types represent a spectrum of possibilities. Some experimentation to find the right shoe for your foot may be necessary. Take the time to seek out a running shoe specialty store where you can try on the shoes and take them for a brief test run before buying.
I welcome questions or comments at orthoman (at) hotmail.com.
Rocco Foot and Ankle Institute
Orthopedic Foot and Ankle Surgery, Lower Extremity Trauma